This invention relates to a ball, a plug or a butterfly valve. These valves have a stopper that interrupts fluid flow in a system lined when rotated 90.degree.. In conventional valve designs, a shaft is attached to the stopper and actuated by an external handle. The shaft is surrounded by a ring or rings of packing that maintain the pressure in the valve.
This invention relates to magnetically actuated packless valves for high pressure applications. Related patents pertaining to magnetically actuated valves, but not especially for high pressure environments say in excess of 2000 psi, are described in U.S. Pat. Nos. 3,347,262 and 3,747,892. Aspects of this invention relate to my own U.S. Pat. No. 4,106,825.
The known advantage of magnetically actuated valves is the elimination of the stuffing box which has always been a drawback. However, in the past, the use of these valves has been confined to relatively low pressures. The principal reason has been that sufficiently strong permanent magnets did not exist that would actuate the magnetic valve through the thick walls required to contain high pressures. Newly available permanent magnets permit the use of thicker walls in the valve housing providing the possibility of magnetically actuated valves for use at high pressures.
It is an object of this invention to provide a magnetically actuated valve for high pressures which will reliably open and close at minimal torques even at pressures in excess of 2000 psi. It is a further object to provide a magnetically actuated ball valve that is pressure tight at pressures exceeding 5000 psi. It is a further object to provide a self-centering valve structure that automatically positions the stopper at the correct position for proper sealing. It is a still further object to provide a magnetically actuated valve with a fail-safe manual override. It is yet another object to provide a ball valve with a unique sealing structure suitable for high pressure environments which permits a greater amount of seal wear before the seals need to be replaced.